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GoldenRice
Vitamin A Deficiency in 2005, vitamin A deficiency affected 190 million children, and 19 million pregnant women throughout 122 countries. It's one of the leading causes of irreversible blindness in the world (500,000 cases annually) and is responsible for 1.2 million deaths a year, as well contributing to millions of cases of xerophthalmia (inability to produce tears). VItamin A deficiency is endemic in southern and eastern asia, where it is mostly diagnosed due to dietary deficiencies. Rice, the main staple in many of those regions, completely lacks vitamin A as well as other important nutrients like vitamin C and K. Effect of VAD Vitamin A in humans is responsible for providing our bodies with retinol, retinal, retinoic acid and several carotenoids. It has multiple functions, and is important for growth and development, maintenance of our immune system, and good vision. Without vitamin A, our retina cannot form retinal, resulting in a lack of rhodopsin, a light absorbing molecule in our eyes. Without vitamin A, our immune systems cannot properly fight off infections, and diseases that we have vaccines against such as measles can become prevalent in patients with vitamin A deficiency. Golden Rice The rice plant is naturally capable of producing Vitamin A, but in the leaves of the plant during photosynthesis, and not the endosperm. In order to tackle the task of curing a preventable disease such as vitamin A deficiency, Ingo Potrykus of the Swiss Federal Institute of Technology and Peter Beyer of the University of Freiburg set out on an eight year long project to biosynthesize beta-carotene into the edible parts of rice, more specifically the endosperm. Their scientific research was published in 2000, and since then researchers have been attempting to incorporate more beta-carotene into this genetically modified organism. In 2005, Golden Rice 2 was born, housing up to 23 times more beta-carotene. Their research began with the discovery that a single phytoene desaturase gene (commonly known as ''bacterial crt1) ''can be used to produce lycopene from phytoene in genetically modified tomatoes. This produced lycopene can then be cyclized in the endogenous activity of the endosperm to beta-carotene, providing vitamin A precursor molecules in our diet. This transformation of parental strains of rice requires two beta-carotene biosynthesis genes. The first biosynthesis precursor is, phytoene synthase, is a transferase enzyme that catalyzes the conversion of geranylgeranyl pyrophosphate to phytoene. Phytoene synthase is generally harvested from ''Narcissus pseudonarcissus ''(daffodils) while the bacterial crt1 gene, carotene desaturase comes from Erwinia uredovora, a gram-negative enterobacteriaceae. These two genes were selected specifically because both of these genes are controlled by a promoter that is specific to the endosperm of the rice plant. Allowing scientists & researches to be sure that the vitamin A being produced is actually in the edible portion of the plant. In natural conditions, the synthesis of carotenoids requires many enzymes and many steps of catalyzing the appropriate compounds to produce lycopene, but ctr1 is able to catalyze the majority of those steps by itself, proving to be incredibly efficient in producing lycopene. Lycopene by itself, would produce a robust red color, but the plant's mechanism of converting lycopene to beta-carotene is what gives it the inherent golden color that it was named after. Application Golden rice field tests are currently being administered in the Philippines and parts of Taiwan. The golden genetically modified rice is bred with local rice cultivars and what they found is astonishing. Field grown rice in these areas produces on average 4-5 more times of beta-carotene than golden rice grown under greenhouse conditions. As of right now, golden rice poses no environmental risk when grown and could potentially improve the economy in regions where rice is a main staple. Both Rutgers University and the University of California conducted studies showing “higher crop yields, reduced pesticide use and fewer pesticide-related health problems” amongst farmers who used GM rice strains. http://www.goldenrice.org/